In Sql Server, often times when I\'m testing the body of a stored procedure, I copy the body into SSMS, DECLARE the variables at the top of the page, set them to some sample
Variables are not defined, but declared.
This is possible duplicate of declare variables in a pl/sql block
But you can look here :
http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/fundamentals.htm#i27306
http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/overview.htm
UPDATE:
Refer here : How to return a resultset / cursor from a Oracle PL/SQL anonymous block that executes Dynamic SQL?